Geospectra-IDMALAB
The case of the Milpillas chalcocite-covered pyrite: an example of bad practice

The case of the Milpillas chalcocite-covered pyrite: an example of bad practice

Some time ago, beautiful specimens of pyrite crystals from Milpillas mine (Mexico) covered by a thin layer of chalcocite (Cu2S),...

The hopper gold crystals from Serra do Caldeirao, Mato Grosso (Brazil)

The hopper gold crystals from Serra do Caldeirao, Mato Grosso (Brazil)

I received a beautiful sample of native gold for its quantitative analysis. The sample is not the typical nugget. Instead,...

Sulfur inclusions in celestite

Sulfur inclusions in celestite

From an old collection specimen, a client sent us some crystal fragments of an unknown species. The crystals were clear,...

A ‘martian’ solution for a mineral problem: chalcocite coating on pyrite

A ‘martian’ solution for a mineral problem: chalcocite coating on pyrite

Our friends from Fabre Minerals asked us an interesting mineralogical question: what is the species present in the beautiful specimens of copper sulfide-coated...

The extraordinary finding of uranyl minerals at Assunçao mine (Viseu, Portugal)

The extraordinary finding of uranyl minerals at Assunçao mine (Viseu, Portugal)

The Assunçao or Nossa Senhora da Assunçao mine, in Aldeia Nova, Ferreira de Aves, Sátao (Viseu, Portugal), benefits industrial minerals from...

Bertrandite from Portuguese pegmatites

Bertrandite from Portuguese pegmatites

The beryllium sorosilicate Bertrandite (Be4(Si2O7)(OH)2) is one of the most important beryllium minerals that could be found in granitic pegmatites....

The chromate-rich mimetite from Nakhlak (Iran)

The chromate-rich mimetite from Nakhlak (Iran)

Description of the chromium-rich mimetite from Nakhlak mine (Iran)

The Olshanskyite and other minerals from Shijiangshan (Ulanhad League, Inner Mongolia, China).

The Olshanskyite and other minerals from Shijiangshan (Ulanhad League, Inner Mongolia, China).

The description of the Olshanksyite from Shijiangshan (China)

Volborthite and tangeite from Milpillas mine (Mexico)

Volborthite and tangeite from Milpillas mine (Mexico)

The Milpillas mine (Municipio de Santa  Cruz, Sonora, Mexico) benefits a porphyry copper deposit, characterized by a potent oxidation zone and...

European Association of Geochemistry Photo Contest

European Association of Geochemistry Photo Contest

    Recently, we won the EAG Photo Contest with a photomicrography entitled Destructive Beauty: The picture shows crystals of neoformed Epsomite...